Analytical approach for evaluation of thermo hydraulic performance of roughened solar air heater

Mathematical modeling and simulations are seen as vital methodologies to predict the thermal performance optimization of thermal systems. Solar air heater roughened with 20° angled rib is simulated using an algorithm developed in MATLAB to predict the optimal set of design and operating parameters. Correlations developed using second order polynomial are used for simulations. In the entire range of flow rates, the thermal efficiency of the roughened solar air heater is higher as compared to smooth duct. In fixed value of solar insolation, thermal efficiency increases with the increase in mass flow rate while effective efficiency decreases. The effective efficiency of the system increases with an addition in the number of glass covers and width of the duct. Thermal and effective efficiency increases with the increase in solar insolation. An increase in velocity increases the convective heat transfer coefficient of air, which reduces the useful heat gain by increasing the top losses which in turn affects the increase in effective efficiency for the rise in velocity in the solar air heater. The effect of mass flow rate, the number of glass covers, heat flux, velocity and variation in width of duct on thermal and effective efficiencies of roughened solar air heater are presented in the form of plots in the present study.